Type one diabetes usually appears before people reach the age of 40. It accounts for between five and 15 per cent of diabetes cases.
Brazilian and US researchers gave 15 newly diagnosed patients with type one diabetes a high dose of immunosuppresion to prevent further destruction of their pancreatic cells.
They followed this with a process known as AHST, which removes and treats stem cells from the patient's blood and then returns them via intravenous injection.
During a seven- to three-year follow-up, the researchers found that 14 patients became insulin free. In one person this lasted for 35 months while another four were insulin free for at least 21 months; seven for at least six months; and two with late response were insulin-free for one and five months respectively.
Writing in the Journal of the American Medical Association, the researchers describe the results as "very encouraging".
"Further follow-up is necessary to confirm the duration of insulin independence and the mechanisms of action of the procedure," they add.
"In addition, randomised controlled trials and further biological studies are necessary to confirm the role of this treatment in changing the natural history of type one [diabetes] and to evaluate the contribution of hematopoietic [blood] stem cells to this change."
Commenting on the study, Dr Jay Skyler of the Diabetes Research Institute said that if further studies confirm these findings then "the time may indeed be coming for starting to reverse and prevent type one [diabetes]".
Dr Iain Frame, research manager at Diabetes UK, described the study as "interesting" but warned against possible "false hope" due to the "preliminary nature" of the results.
"This study had a very small number of participants and importantly did not include a randomised control group for comparison of results. Also, as the researchers say, those who took part have not been sufficiently followed up to find out whether or not the improvements in their C-peptide levels have continued," he said.
"It is well known that there is often a honeymoon period of relative remission after the onset of type one diabetes that complicates the interpretation of results such as the ones shown in this study. All these issues need to be addressed through more research before there are any conclusive findings in this area."
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